COLVENT™ TG is a SBS-modified bitumen base ply for use in approved multi-ply membrane and flashing assemblies. COLVENT TG is composed of a proprietary formulation of elastomeric styrene-butadiene-styrene (SBS) polymer modified bitumen in combination with partially adhered ribbons and is reinforced with a high quality random glass fiber mat. The ribbon strips are arranged in a pattern to vent vapor pressure between the substrate and the COLVENT TG. The topside is surfaced with fine mineral aggregate to optimize cold adhesive and hot asphalt applications and the underside is surfaced with polyolefin burn-off film to optimize heat welding.